Hi Guys & Gals,
I've been lurking around on this forum for a while (since I decided to build myself a river boat.)
Take a look at these photos of a 18' Punt built in 1981:
1) 18' AOL x 5' Beam
2) 48" wide & 3/16" thick bottom (dead flat for first 12')
3) Sides are 1/8", empty weight of the boat/motor is 875-900lbs
4) There are 3x 2" channel runners on the bottom. (properly cut-away for unobstructed flow to the pump)
1) With the E-tec 50hp this punt will get on step with 2 guys and a moose aboard... By our standards, this is enough power. As a matter of fact, the fellow who owns this boat used to run a Evinrude "Commercial 45" (with jet) for many years, and still has that set-up on a second identical skiff.
2) When running in a riffle or small chop the motor can/will start cavitating.
3) Draws a little too much water when stopped (sucks up gravel when pulling out of the hole)
I would like to build a similar punt with the following "improvements"
1) 60" wide bottom with 3deg of "V"
2) 18" longer (may as well use up the whole sheet of aluminium lol.)
3) Shallow jet tunnel to get pump out of the riverbed.
1) Will the 3deg of "V" be enough to help with the cavitation issues?
2) I've bought one of the new Merc 60/40 jets... When looking at the pump/impellor specs; I see it runs a 6 7/8" impellor in the "large" bowl size verses the E-tec's 6 1/8" in the "medium" bowl. I've made the assumption that the Merc should have a little better torque for getting out of the hole... Tell me I'm right.! lol
Goggle-Earth the Kliniklini River (Knight Inlet, BC)